The poll, done May 17-20 exclusively for the Detroit Free Press, WXYZ-TV in Detroit and our statewide media polling partners by EPIC-MRA of Lansing, found that if a vote on allowing same-sex marriage in Michigan were held today, 47% would vote yes and 46% would vote no. The remaining 7% were either undecided or refused to say.

When EPIC-MRA asked Michiganders about same-sex marriage in May 2013, 51% said they supported it and 41% said they were opposed. Both polls sampled 600 likely voters and had margins of error of plus or minus 4 percentage points.

Bernie Porn, president of EPIC-MRA, said he's surprised by the result. He said, it's too early to say whether the poll is a statistical outlier or represents a shift in the public mood over the last year, as same-sex marriage has garnered considerable media attention due to a federal lawsuit in Detroit and significant court rulings in Michigan and other states, he said.

It's possible some Michiganders have pulled back on the same-sex marriage issue in the face of that publicity, Porn said. It's also possible the most recent poll had a somewhat skewed result because it drew a lower proportion of presidential election voters - who tend to be younger than those who vote in mid-term elections - than the poll he conducted last year.

The shift in the poll numbers comes as residents await a federal appellate court ruling affecting about 300 gay couples who were married in March, when it was briefly legalized in Michigan - and many more of the state's same-sex couples who would like to do so.

The 2013 poll was one of several Michigan polls showing a trend toward support of same-sex marriage since 2004, when Michigan voted 59% in favor of defining marriage as between one man and one woman.

The latest poll showed huge differences on same-sex marriage among age and gender groups, income groups, political party affiliation, education, and regions of the state.

The only voter age group that supports same-sex marriage is the youngest one, ages 18 to 34, where support is 68% for and 28% opposed. Those between the ages of 35-49 oppose same-sex marriage 49%-46%, while those between 50-64 oppose it 47%-46%, and those 65 and older oppose it 54%-37%, the poll shows.

"Why should anybody have to be discriminated against?" asked Nicole Nasr, 26, a Macomb County resident who is a master's degree student in social work at Michigan State University.

Nasr, who participated in the survey, said she has friends in the lesbian, gay, bisexual and transgender community, supports same-sex marriage, and believes the trend in public opinion is moving her way.

Guyton Adams, 84, of Southfield, a retired U.S. Postal Service finance clerk who also participated in the survey, said he's opposed to same-sex marriage on religious and moral grounds.

"The Bible says a man and a woman," Adams said. "If you're going to change it to a man and a man, or a woman and a woman, that's something else."

On March 21, U.S. District Judge Bernard A. Friedman struck down Michigan's same-sex marriage ban as unconstitutional following a lawsuit brought by a lesbian couple alleging discriminatory adoption rules. Clerks in four Michigan counties opened their offices the next morning, allowing about 300 same-sex couples to marry before the U.S. 6th Circuit Court of Appeals stayed Friedman's order and halted the marriages later that day.

The case is now set for arguments before the 6th Circuit on Aug. 6 and could be headed for the U.S. Supreme Court.

Michigan Gov. Rick Snyder, a Republican who said in a 2010 debate he believes marriage is between one man and one woman but has refused to state his position since taking office in 2011, has said the marriages were performed legally but Michigan can't recognize them or grant the couples marital rights while the state's appeal of the ruling is pending.

Breaking down the most recent results further, 43% of those surveyed gave a firm "yes" to same-sex marriage, while another 4% said they were leaning toward voting yes. Of the no votes, 46% were firm and 1% was leaning toward no.

Men opposed same-sex marriage 52%-42%. And women support it, 51%-41%.

Democrats support same-sex marriage 69%-25%, Republicans oppose it by almost the same numbers 70%-25%, and Independents narrowly oppose it 46%-44%, the poll found.

That's a significant shift from 2013, when self-described Independents said they supported same-sex marriage, 51%-41%.